Mono.CSharp.DefaultParameterValueExpression.Resolve C# (CSharp) Method

		public void Resolve (ResolveContext rc, Parameter p)
		{
			var expr = Resolve (rc);
			if (expr == null)
				return;

			expr = Child;

			if (!(expr is Constant || expr is DefaultValueExpression || (expr is New && ((New) expr).IsDefaultStruct))) {
				rc.Report.Error (1736, Location,
					"The expression being assigned to optional parameter `{0}' must be a constant or default value",
					p.Name);

				return;
			}

			var parameter_type = p.Type;
			if (type == parameter_type)
				return;

			var res = Convert.ImplicitConversionStandard (rc, expr, parameter_type, Location);
			if (res != null) {
				if (parameter_type.IsNullableType && res is Nullable.Wrap) {
					Nullable.Wrap wrap = (Nullable.Wrap) res;
					res = wrap.Child;
					if (!(res is Constant)) {
						rc.Report.Error (1770, Location,
							"The expression being assigned to nullable optional parameter `{0}' must be default value",
							p.Name);
						return;
					}
				}

				if (!expr.IsNull && TypeSpec.IsReferenceType (parameter_type) && parameter_type.BuiltinType != BuiltinTypeSpec.Type.String) {
					rc.Report.Error (1763, Location,
						"Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
						p.Name, parameter_type.GetSignatureForError ());

					return;
				}

				this.expr = res;
				return;
			}

			rc.Report.Error (1750, Location,
				"Optional parameter expression of type `{0}' cannot be converted to parameter type `{1}'",
				type.GetSignatureForError (), parameter_type.GetSignatureForError ());
		}
	}